This relates generally to electronic devices with displays, and, more particularly, to light sources for displays.
Electronic devices such as computers and cellular telephones have displays. Some displays are based on light-emitting diodes. For example, organic light-emitting diode displays have arrays of organic light-emitting diodes. Light-emitting diode displays based on arrays of crystalline light-emitting diode dies have also been developed. Liquid crystal displays have arrays of liquid crystal pixels that are backlit using backlight structures based on light-emitting diodes. These light-emitting diodes may be arranged in an array to support local diming or may be used to edge light a light guide plate in a backlight unit.
Display performance can be enhanced by using narrow linewidth light-emitting diode light sources. For example, color saturation in a display can be enhanced by using light-emitting diode sources that emit narrowband red, green, and blue light. Light sources of this type may exploit the ability of phosphors and quantum dots to produce output light of desired wavelengths and linewidths. For example, a display may include red and green quantum dots to convert some of the blue light from a blue light source to narrowband red and green light.
There are challenges associated with forming this type of display. Quantum dots and phosphors can be sensitive to moisture and oxygen. Quantum dot lifetimes can also be adversely affected by exposure to high pump light intensities and elevated temperatures. Quantum dot performance is also affected by the type of structures used to form the quantum dots. If care is not taken, quantum dots will exhibit insufficient quantum confinement and instability.
It would therefore be desirable to be able to provide enhanced light sources for display.